The present invention relates generally to devices for mixing a plurality of fluids and more particularly to such devices commonly characterized as "motionless" in that they employ no moving parts.
Conventional motionless mixing devices typically provide a tubular housing through which two or more fluids to be mixed are caused to flow, ordinarily under pressure, and in which housing a plurality of stationary helical baffle members are serially disposed for progressively dividing and subdividing the liquids to effect the mixing thereof. Representative examples of such motionless mixing devices are disclosed in U.S. Pat. Nos. 3,286,992; 3,664,638; and 3,704,006.
Mixing devices of this type have proved satisfactory for the mixing of fluids of approximately the same viscosity but have been found to perform unacceptably to mix fluids of widely varying viscosities because of the tendency of such fluids for laminar flow with the less viscous fluid flowing primarily centrally through the device where the baffles thereof have little mixing effect on such fluid, this effect being commonly referred to in the art as channeling. A lengthy mixing device or multiple mixing devices could be employed to achieve better intermixing of such fluids, but the attendant space requirements and cost of such a mixing arrangement would ordinarily be prohibitive.
This problem has been recognized in U.S. Pat. No. 3,953,002, which discloses the use of tapered cylindrical links spacing apart the several baffle members of an otherwise conventional mixer of the above-described type to disperse any fluid tending to channel centrally in the mixer. While this mixer provides an acceptable improvement over conventional mixers in achieving better mixing of fluids of differing viscosities, it nevertheless is generally incapable of mixing such fluids to the degree achieved by conventional mixers in mixing fluids of comparable viscosity.
In contrast, the present invention provides an improvement in the latter type motionless mixing device which is operable to turbulently diffuse outwardly from the center channel thereof the portion of fluids flowing therealong in a manner which is effective to achieve mixing of fluids of varying viscosities to a degree comparable to that achieved conventionally in mixing fluids of the same viscosity.